Field of the Invention
The present invention relates to an image processing apparatus configured to analyze a video image, and, in particular, to a setting of a region in which a video image is analyzed.
Description of the Related Art
Conventionally, it has been possible to analyze a captured image, based on a result of detection of a change in an object in a video image, to detect: whether the object is moving in the captured image, whether the object is left behind, whether the object is carried away, whether the object has passed across a predetermined region, whether any mischief is made on a camera, and the like. Further, it has been possible to track the object in the captured image based on the result of the detection of the change.
Japanese Patent Application Laid-Open No. 2005-312018 discusses a method according to which, when analyzing a captured image acquired by a network camera, an image processing apparatus specifies only a part of a region in the captured image as an analysis region to analyze the image within the specified region.
Further, Japanese Patent Application Laid-Open No. 2010-103676 discusses a method in which a network camera switches an aspect ratio of a captured image to be output, or switches an aspect ratio of a captured image to be recorded in recording processing.
Japanese Patent Application Laid-Open No. 2010-103676 discusses a method according to which the camera switches a range to be actually displayed on a display device, within an imageable range in the captured image as a method for switching the aspect ratio of the captured image.
Japanese Patent Application Laid-Open No. 2010-103676 discusses an example in which the camera switches the aspect ratio of the captured image to be displayed from 16:9 to 4:3. Japanese Patent Application Laid-Open No. 2010-103676 discusses that, in this example, the camera changes the aspect ratio of the captured image to be displayed to 4:3 by refraining from displaying left and right portions of a region in the captured image that was displayed when the aspect ratio was 16:9.
Not only in this example but also in some other cases, changing the size of the captured image to be displayed on the display device may result in disappearance of a part of the image that was displayed before the change. Alternatively, displaying the captured image while changing the size of the captured image to be displayed may result in appearance of an image that was not displayed before the change.
The analysis method discussed in Japanese Patent Application Laid-Open No. 2005-312018 has not been contrived in consideration of these cases in which a display range of the captured image (for example, the aspect ratio of the captured image) is changed after the analysis region is specified. If the display range of the captured image is changed after the analysis region is specified, the analysis region may have to be specified again.
For example, the following problem may arise if a change in the aspect ratio of the captured image to be displayed results in disappearance of a part of the captured image that was displayed before the change. In this case, if the analysis region is at least partially contained within this range that becomes undisplayed, the range of the analysis region also has to be reduced.
Further, for example, the following problem may arise if a change in the aspect ratio of the captured image to be displayed results in appearance of the captured image that was not displayed before the change. In this case, if a user wants to also set the analysis region in this range that becomes displayed, the range of the analysis region has to be set again.
Further, for a setting of a detection line for use in passage detection processing, for detecting that an object has passed across a predetermined line, the detection line may also have to be set again according to the change in the display range of the captured image.
Requiring the user to specify the analysis region or the detection line again each time the display range of the captured image is changed causes the user to perform cumbersome processing.